Okay, sounds good. Thanks. Now if I could just figure out how to cause it to happen...
> If you are on a UNIX jvm, issue a signal 3 (SIGQUIT) to the jvm process > when tomcat stops responding. It will dump on standard-out (normaly > redirected to catalina.out) the list of Threads with a stacktrace for > each. By invstigating stacktrace you will get clues as where the problem > is. I don't know if mysql is protected against deadlocks, but it may be > user1 locks ressource X, user2 locks ressource Y, user1 wait for Y to > free, user2 wait for X to free, all other users are waiting for X to > free, filling in the ThreadQueue, tomcat then look like unresponsive. > > Of course the same kind of concurrency issue can occurs with > synchronized{} blocks > > Note, you can also get such dump on windows, it requires you to press > magic key combinaison in JVM terminal (don't remember which) > tc a écrit : >> I have been asked to investigate a tomcat/java application. >> >> The basic problem is that this application sometimes becomes >> unresponsive >> if more than one user uses it at a time. Restarting Tomcat clears the >> problem. I don't think it has ever occurred when only one person was >> using the app. >> >> It is a fairly straight forward data-entry app; the data is stored in a >> mysql database. >> >> The developers think there may some issue with the database. They have >> also done multi-user testing without being able to reproduce the >> problem. >> >> I'm looking for pointers to any resources on the web or elsewhere that >> can >> help me track down the problem, or ideas about where to look, or what we >> can do to improve post-freeze diagnosis of this problem. >> >> I am also a developer, but I don't have a lot of experience with Java or >> Tomcat. I'm trying to bring a fresh perspective to this problem. >> >> Thanks. >> >> >> --------------------------------------------------------------------- >> To start a new topic, e-mail: users@tomcat.apache.org >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]